<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <link rel="stylesheet" href="../reset.css">
  <style>
    .box1,.box2,.box3{
      font-size: 50px;
      width: 200px;
      height: 200px;
    }

    .box1 {
      background-color: #bfa;
      position: absolute;
      /*z-index: 9;*/
    }
    .box2{
      background-color: rgba(255,0,0,0.3);
      position: absolute;
      top: 100px;
      left: 100px;
    }
    .box3{
      background-color: yellow;
      position: absolute;
      top: 200px;
      left: 200px;
    }
  </style>
</head>
<body>
<div class="box1">1</div>
<div class="box2">2</div>
<div class="box3">3</div>
</body>
</html>